So cellulose does contain the basic carbon structures needed to build petrochemicals. As demonstrated by your equations.
The carbon-chain sections in cellulose could be changed to chemicals that, at present, are mostly made from petroleum eg. Propene, butene. If a chemical process can be developed or a micro-organism found that can break the glucose into these smaller carbon-chains this would be very useful.
Biomass is a huge resource. Two main obstacles are: 1- Cost- it takes a lot of energy to grow, harvest and then process the crops. We do not have economic technologies to process cellulose… yet..? 2- Land – Most fertile land is already being used to grow crops. Is it ethical to use land to grow crops entirely for their cellulose when people in Some parts of the world do not have enough to eat? Solutions?
Solutions 1- Research into making the conversion of cellulose into useful chemicals more economical. 2- Use waste products of crops that would normally be discarded.